Regenerate MANIFEST.json when WPT tests are run

third_party/WebKit/Tools/Scripts/webkitpy/layout_tests/controllers/manager.py

Index: third_party/WebKit/Tools/Scripts/webkitpy/layout_tests/controllers/manager.py
diff --git a/third_party/WebKit/Tools/Scripts/webkitpy/layout_tests/controllers/manager.py b/third_party/WebKit/Tools/Scripts/webkitpy/layout_tests/controllers/manager.py
index 73311ca6072e0864cb7f8e0db1ead66dd02e08b3..29580d9064cbbba67d2671bc785ebeacf521d601 100644
--- a/third_party/WebKit/Tools/Scripts/webkitpy/layout_tests/controllers/manager.py
+++ b/third_party/WebKit/Tools/Scripts/webkitpy/layout_tests/controllers/manager.py
@@ -44,6 +44,7 @@ import sys
 import time
 
 from webkitpy.common.net.file_uploader import FileUploader
+from webkitpy.common.webkit_finder import WebKitFinder
 from webkitpy.layout_tests.controllers.layout_test_finder import LayoutTestFinder
 from webkitpy.layout_tests.controllers.layout_test_runner import LayoutTestRunner
 from webkitpy.layout_tests.controllers.test_result_writer import TestResultWriter
@@ -71,6 +72,7 @@ class Manager(object):
           printer: A Printer object to record updates to.
         """
         self._port = port
+        self._executive = port.host.executive
         self._filesystem = port.host.filesystem
         self._options = options
         self._printer = printer
@@ -88,6 +90,7 @@ class Manager(object):
 
         self._results_directory = self._port.results_directory()
         self._finder = LayoutTestFinder(self._port, self._options)
+        self._webkit_finder = WebKitFinder(port.host.filesystem)
         self._runner = LayoutTestRunner(self._options, self._port, self._printer, self._results_directory, self._test_is_slow)
 
     def run(self, args):
@@ -95,6 +98,18 @@ class Manager(object):
         start_time = time.time()
         self._printer.write_update("Collecting tests ...")
         running_all_tests = False
+
+        wpt_tests_in_test_list = False
+        if self._options.test_list:
+            for test in self._options.test_list:
+                if test.startswith('external/wpt'):
+                    wpt_tests_in_test_list = True
+                    break
+
+        # TODO(jeffcarp): unit test
+        if wpt_tests_in_test_list or not self._options.test_list:
+            self._generate_manifest()
+
         try:
             paths, test_names, running_all_tests = self._collect_tests(args)
         except IOError:
@@ -545,3 +560,14 @@ class Manager(object):
         for name, value in stats.iteritems():
             json_results_generator.add_path_to_trie(name, value, stats_trie)
         return stats_trie
+
+    def _generate_manifest(self):
+        _log.info('Generating MANIFEST.json, this might result in changes to MANIFEST.json\n'

[foolip, 2017/02/16 07:20:26]

I have verified that removing MANIFEST.json from the repo entirely, this still
works. It's slow the first time, but quite fast the second time.

In https://bugs.chromium.org/p/chromium/issues/detail?id=666957#c24 I suggested
we just delete MANIFEST.json and then try to optimize the first run. The message
here could be changed to "Generating MANIFEST.json, this can be slow.
https://crbug.com/666957" and then removed entirely when it's no longer slow.

+                  'in your working directory. Please commit them along with your changes.\n'
+                  'See https://crbug.com/666957.')
+
+        wpt_path = self._webkit_finder.path_from_webkit_base('LayoutTests', 'external', 'wpt')
+        manifest_tool_path = self._webkit_finder.path_from_webkit_base(
+            'Tools', 'Scripts', 'webkitpy', 'thirdparty', 'wpt', 'wpt', 'manifest')
+
+        self._executive.run_command(['python', manifest_tool_path, '--work', '--tests-root', wpt_path])